Most people use GPS to help them find their way, but J.A. Konrath, author of the Lt. Jacqueline "Jack" Daniels thriller series, used it to help find more bookstores to promote his books in:
To promote the first book, Konrath's publisher sent him out on an 11-bookstore tour. But by utilizing the GPS device in his rental car, he ended up visiting 106 bookstores on that tour.Via Wired News.
His ability to use the technology to find more places to promote his book impressed his publisher enough that this summer, Hyperion is sending Konrath out for a two-month, 500 bookstore tour.